When something stops working

When a computer system stops working

A problem which stops something working

A problem which stops something working as well as it should be

Harm to something or somebody

Physical harm to somebody

When a problem is dealt with and fixed

When someone says there is a problem with something 

When a company gives the customer their money back

When a company asks the customer to bring the product back

When you understand something in a different way from what is meant

When you do something the wrong way